The closest synonym for the word adherent is: A. Proponent.
Adherent basically is similar to the loyalty and attachment to a party
Proponent means a person who advocates a theory proposal - defender, follower, enthusiast Informant is someone who tells someone something Agnostic is someone who believes nothing is known Financier is someone concerned with managing money
Therefore we can see proponent would be the closest synonym as a proponent advocates a theory proposal so they stick to it, are loyal, supportive and backs up something. This is similar to adherent which means someone who supports a particular party.
Because they believed that women's suffrage would help secure progressive reforms; women were frustrated that they weren't directly influencing reform. Hope this helps!
